"Hyperacusis" is an extreme aversion and hypersensitivity to sounds that are generally not an issue to others.
Electrical and machine noises, as well as sudden high-pitched noises, are usually hard to tolerate for people with hyperacusis.
However, any sound can potentially trigger a reaction in someone with hyperacusis – even the sound of their own voice.
The abnormal reaction may have happened suddenly or got worse gradually over time.
It's very different from the reduced tolerance for noise that most of us have when we're tired or stressed, or reacting to an obviously unpleasant noise, such as chalk scratching a blackboard.
Hyperacusis can be just a minor nuisance for some, with people feeling uneasy or uncomfortable when they hear the noise.
For others, it can have a major impact on life. Low-level noises may be perceived as intrusively loud and may trigger [anxiety].
Noise can be painful for people with severe hyperacusis. High-pitched sounds can be felt as 'a nail being driven into the head' and low-pitched thrumming 'like sandpaper moving across the brain'.
Some react by covering their ears or leaving the room. Crying, anger and panic reactions are not uncommon.
As a result, people with hyperacusis may avoid noisy situations and become socially isolated. People with severe hyperacusis may feel suicidal.
Noises that are commonly an issue for children with hyperacusis include:
Children with hyperacusis may struggle at school, where background noise can make it difficult for them to concentrate, thereby affecting their achievement. Some will need professional help in this critical period of their lives, but they may grow out of the problem over time.
However, this does not seem to be the case for adults with hyperacusis. If a sound triggers pain or discomfort, the fear or anxiety this sound provokes only makes the condition worse.
Hyperacusis is estimated to affect between 7% and 23% of the UK adult population.
It's estimated to affect between 12% and 27% of children, and is particularly common in children with Williams syndrome, autistic spectrum disorder and tinnitus (see below).
The cause of hyperacusis is unclear.
Some of the theories are explained below, but for many people, hyperacusis can occur for no apparent reason.
Hyperacusis sometimes occurs in people with hearing loss. For people with hearing loss, the sound signals from the inner ear to the brain will be weaker than normal, and it's possible that the brain amplifies these signals too much to compensate, resulting in hypersensitivity.
However, this doesn't explain the cause in those with hyperacusis and no hearing loss.
Many children and adults with hyperacusis have a medical condition, such as:
It may be that the condition or disease has affected their hearing system in some way and the brain has overcompensated for this, like it does when there's hearing loss.
People with hyperacusis typically experience negative emotions when they hear certain noises.
The sound may be linked to a previous upsetting experience or to negative thoughts they've had about it previously. This means that every time they hear the noise, it automatically triggers a "fight or flight" response and fear, anger, anxiety or irritation.
This would explain why hyperacusis is sometimes associated with post-traumatic stress disorder (PTSD).
For some, hyperacusis may have developed after:
Hyperacusis is a difficult problem to study and diagnose because it is a subjective experience that is hard to measure.
Anyone who has a severe sound intolerance should see their doctor. They may be referred to an ear, nose and throat (ENT) consultant or a hearing disorders specialist (audiologist) to have a hearing test.
This test involves listening through headphones to sounds of increasing intensity, and pressing a button when the sound becomes uncomfortably loud. Self-reporting questionnaires can also be used to measure how much hyperacusis affects the person's life.
Doctors will want to rule out any medical condition that may be causing hyperacusis. Treating the former may cure the latter.
If the underlying cause isn't certain or there's no obvious treatment, a referral may be needed for retraining counselling and sound therapy.
This therapy is widely available privately, and may be available on the NHS for people with very severe or persistent hyperacusis. It should only be carried out by someone specially trained in the technique.
Some people may also be advised to have cognitive behavioural therapy (CBT).
Hyperacusis is thought to result from the brain amplifying sound signals too much. Retraining counselling and sound therapy aim to modify this brain response by removing negative emotional associations to sound.
Retraining counselling teaches patients how emotions and the nervous system may play a role in hyperacusis, and encourages them to reclassify troublesome noises as neutral signals.
Sound therapy helps this process by temporarily desensitising the hearing system so that the individual can go to noisy places without being constantly affected by them. "Desensitising" means listening to and gradually getting used to the sound, which is achieved through the use of noise generators.
Noise generators are small devices worn like hearing aids. They produce a steady, gentle noise with a volume control, allowing the noise level to be turned up or down.
The sound is fed into the ears through an ear mould, which is designed not to block the ear canal, allowing background noise to be heard normally.
It's used to improve a person's ability to tolerate normal exposure to sound – the ear gradually gets used to it and becomes less sensitive.
There is no possibility that hearing will be damaged through using a noise generator, and benefits have been shown even when the generator is not in use.
This is an established method of treating hearing oversensitivity and is used in many audiology departments in the UK.
Initially, the aim is to increase the length of time the device is worn to at least six hours a day.
The volume should be set so the noise it generates is just about audible, and not intrusive.
If the background noise level is uncomfortable, the volume can be increased to cope with the discomfort.
When the device can be used comfortably for six hours a day without any problems, the level of the noise output should be gradually increased, little by little. The new level should not cause problems, although it may take time to adjust to it.
There is no set level that must be reached, but when the person can tolerate all noises with the generator on, there the volume does not need to be increased any more.
At this point, they shouldn't need to rely on using the device so much, and can gradually reduce the volume or the hours of use.
Typically, after using a noise generator for 12 to 18 months (about 7 appointments), most people find a long-term improvement in their sensitivity, without needing to use the device.
Some people also find the following tips helpful:
Cognitive behavioural therapy (CBT) is recommended for people with hyperacusis who also have anxiety and depression, or for those who did not benefit from retraining therapy.
CBT is based on the idea that a person's thoughts affect the way they behave. It aims to retrain the way a person thinks in order to change their behaviour – this may be helpful for people who feel a strong emotional response, such as anxiety, to noises.
The aim is to enable the patient to identify and modify their troublesome thoughts. This helps reduce the anxiety and depressed mood, and allows them to accept the noises, which may become less noticeable after a while.
Important: Our website provides useful information but is not a substitute for medical advice. You should always seek the advice of your doctor when making decisions about your health.